Altcha - SHA-256 Challenge Solver

A high-performance Go implementation of a bidirectional hash challenge solver using parallel processing to find a number that, when combined with a salt and hashed with SHA-256, produces a specific target hash.

Features

• Bidirectional search (searches from both ends simultaneously)
• Parallel processing with configurable number of workers
• Automatic workload distribution among workers

How It Works

The solver employs two main strategies:

1. Bidirectional Search: Splits the search space into two parts:

   • Forward workers search from 0 → middle
   • Backward workers search from maxNumber → middle

2. Parallel Processing:

   • Uses 20 workers (10 forward + 10 backward)
   • Each worker handles a specific range of numbers
   • First found solution terminates all searches

Usage

challenge := Challenge{
    Algorithm:  "SHA-256",
    Challenge:  "<target-hash>",
    MaxNumber: 150000,
    Salt:      "<salt-string>",
}

result := solveChallenge(challenge)

Perfomance

The official documentation states the following benchmarks for complexity of 100,000:

Device	Performance	Time to Solve
MacBook Pro M3-Pro (2023)	3 ops/s	0.33 sec
iPhone 12 mini (2020)	1.2 ops/s	0.83 sec
AWS EC2 (c6a.xlarge)	1 ops/s	1 sec
Samsung Galaxy A14 (2023)	0.4 ops/s	2.5 sec
AWS Lambda (1GB)	0.12 ops/s	8 sec

My implementation needs only ~8ms